21274737653 has 16 divisors (see below), whose sum is σ = 23237760000. Its totient is φ = 19360076544.

The previous prime is 21274737641. The next prime is 21274737689. The reversal of 21274737653 is 35673747212.

It is a cyclic number.

It is not a de Polignac number, because 21274737653 - 2⁴ = 21274737637 is a prime.

It is a super-2 number, since 2×21274737653² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21274737598 and 21274737607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21274737053) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 262973 + ... + 334221.

It is an arithmetic number, because the mean of its divisors is an integer number (1452360000).

Almost surely, 2^21274737653 is an apocalyptic number.

It is an amenable number.

21274737653 is a deficient number, since it is larger than the sum of its proper divisors (1963022347).

21274737653 is a wasteful number, since it uses less digits than its factorization.

21274737653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71588.

The product of its digits is 1481760, while the sum is 47.

The spelling of 21274737653 in words is "twenty-one billion, two hundred seventy-four million, seven hundred thirty-seven thousand, six hundred fifty-three".